1. Field of the Invention
This invention relates to an electronic musical instrument which can generate several tones simultaneously or which can generate specified chords.
2. Description of the Prior Art
At present available are various electronic musical instruments which can generate several tones simultaneously, generate specified chords, or generate automatically rhythm. Also available are instruments which can control the tone generation level by detecting the key depression speed and breath intensity.
These musical instruments have the following functions and faults.
The electronic musical instruments which can generate simultaneously several tones, in general, have some sound source circuits, and the number of musical tones which can be generated simultaneously by one sound generation operation (pressing of keyboard).can be changed. This is enabled by setting beforehand the number of sound sources actuated by one sound generation operation (hereinafter referred to as the number of sound sources) in the electronic musical instrument. However, since the setting of the number of sound sources requires operations of various function keys, it is impossible to do such a setting during playing the instrument. The conventional electronic musical instruments had faults that when the number of sound sources is set to 1, only one musical tone is generated, thereby resulting in poor expression, even though the specified tone is ff(fortissimo), and that when the number of sound sources is set to 2 or more (generally 2 to 8), the sound is heavy and lacks in delicacy, even if the specified tone is pp (pianissimo). Besides, there are other types of electronic musical instruments which allow programming of various types of settings of the sound sources and enable program selection with a simple selection operation. However, this type needs the program change operation, and the program selection can be performed only in a previously specified order. Correct execution of such a program needs training of player to some extent. Accordingly, for beginners this was difficult. Moreover, it was very difficult to change quickly the number of sound sources of the conventional electronic musical instruments during playing, following the change of volume (level).
The electronic musical instruments capable of generating chords generate chords by specifying the root (the lowest tone in a chord (for example, C in the do-mi-so)) and the type (major chord, minor chord, dominant seventh chord, dominant seventh minor chord). For example, keyboard type electronic musical instruments have the following functions.
Pressing one key generates the major chord whose root is the pressed key. PA1 Pressing two keys generates the minor chord whose root is the higher key. PA1 Pressing three keys generates the dominant seventh chord whose root is the highest key.
However, in these electronic musical instruments the data which can be specified are only the root and type of chord, therefore only the specific chord can be generated by one specification. Accordingly, the player cannot give variation of the sound (strong and weak sound), and the music is monotonous. When the player wants, for example, to express a pianissimo tone, a chord consisting of 3 to 5 tones is generated, so that delicacy is lost.
The electronic musical instruments which can generate rhythm incorporate a rhythm generating section. These instruments can generate various rhythms by setting the type of rhythm and tempo. In the electronic musical instruments having an automatic accompaniment function a chord specified by keyboard can be generated as broken chord (arpeggio) based on the rhythm tempo. However, the conventional automatic accompaniment function could only generate one or several tones according to the rhythm tempo, decomposing the specified chord into component sound tones. Therefore, if the player changes the chord during beat, with improper timing, the chord is changed while the broken chord is being generated. For example, when a chord is a sextuplet (one beat) consisting of prime, third, fifth, octave, fifth, and third, and the tonic chord(C chord) is specified, the chord must be generated in the order of "do, mi, sol, do, sol, mi". But, if the specification is changed to the D chord at the next timing to the octave tone generating while a broken chord is generated, the chord generated is "do, mi, sol, do, la, fa#". Thereby a complicated chord is generated. So as to eliminate this failure, the player has to change the chord according to beat timing. Accordingly, playing such an instrument is difficult. The same is valid not only while playing chords, but also while playing a melody in tune with a rhythm.
There are two types of electronic musical instruments which can control the tone generation level. One of them is keyboard type electronic instruments having a function to control the musical tone intensity (tone generation level) by detecting the key depression intensity and speed. Another type is electronic wind instrument which controls the tone generation level by detecting the breath intensity. These electronic instruments are provided with a sensor to detect the above-mentioned intensity (key depression and breath intensity) and a means for converting the detected value into the tone generation level control data. However, the conventional electronic instrument has a defect that the tone generation level varies depending on the player's key depressing force or breath intensity because the detected values are converted into the tone generation level control data always based on a fixed relation. Hence, if an instrument is played by a player with higher key depression intensity or breath intensity, the sensor detection value reaches soon the level of "ff", and he can not play delicately. On the other hand, for a player with lower key depression intensity or breath intensity it is difficult to generate sound of sufficient level (breath threshold). The electronic wind instruments are provided with a breath sensor as shown in FIG. 1 (C). However, it is difficult to uniform their characteristics owing to their structural features, therefore, they differ in the relation between actual breath intensity and tone generation level.
Among all electronic instruments, the electronic wind instruments, in general, have a form and a key arrangement similar to those of woodwind instruments. They are designed so that a specific sound pitch can be specified by setting a playing key to ON or OFF with a fingering pattern similar to that of the woodwind instruments. However, since the actual wind instruments are monophonic instruments, the above-mentioned fingering pattern is set so as to specify a specific single tone. Therefore, most of conventional electronic wind instruments can not specify chords and can generate only single tones. This makes it difficult to use them for accompaniment.